In computer aided diagnosis segmentation tools are used to segment images of medical objects into sub-objects representing relevant physiological features of the object. Examples are COPD (chronic obstructive pulmonary disease) and lung cancer diagnosis segmentation tools that are used to segment a CT (computed tomography) image volume of a left or right lung into its lung lobes.
Fully automated segmentation algorithms are known but do not always yield the desired results. Segmentations so produced will then have to be reviewed and corrected or edited which can be at times cumbersome. This is particularly true for higher than two dimensional segmentations.